Hydraulic jack



June 14, 1949. H. A. THoRNDlKE HYDRAULIC JACK Filed June 20, 1946 2 Sheets-Sheet 1 f A 11x-..

June 14, 1949 H. A. THORNDIKE 2,472,867

` HYDRAULIC JACK A Filed June 2o, 1946 zsrieefs-sheet 2 @im .HE ber? A Thandzk@ Patented June 14, 1949 HYDRAULIC .JACK

.,Herbert A. Thorndike, OshkoshyWis., assignor,

lby mesne assignments, to Vulcan Manufactur- L Ving Co., Inc., Winona, Minn.

. ApplicationJune'Z, 1946,.Se'rial No. 678,048

3 Claims.' (Cl. 10S-228) {Ehis` invention relates to; new andy useful .irnprovements inhydraulic` pumps, andmore particularly `to ahydraulicpumpof the reciprocating type having an improved check valve -assembly.

The hydraulic pump which forms-the subject matter rof this invention. is particularly designed foruse in.v a-hydraulic-jackpsuch as that described vin my-copending applications .Serial Nos. 37.87.,(180 and 928.

vThe checkyalve assemblyof hydraulic jack pumps .is an,especially, critical v unit, andl any .foreignmatter inthe =fluidtends to accumulate around thevalve seats-seriously ,interfering with the .operationof ythe-pump. Frequently such jacks are .,employed ,for general-farm use, and farmers are in the habit of adding any available -fluidto-.the system. when the need arises, even using engine crank-case drainings, Hence it is obvious "that the vcheck-valve assembly in the pump of a hydraulic jack must loe readily -accessible for frequent cleaning.

It is therefore an object of this invention to provide a, compact hydraulic fpump, especially adaptable for use with a jack, which may easily be, ,disassembled for cleaning with only afew -ordinary tools.

y A; further object 'of' this invention isthe provision- `of" a unitary valve assembly for a reciprocating type of hydraulic pump which can be removed from the pump for cleaning or replacement by merely removing the pump cylinder.

Still another object of this invention is to provide a unitary valve assembly for a hydraulic pump which may be cheaply and easily constructed, and which will serve as the end wall of the pump cylinder and also as a gland to afford a uid tight seal in the cylinder.

With the above and other objects in View which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate one complete example of the physical embodiment of the invention constructed in accordance with the best mode so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a view in elevation of a hydraulic jack havingthe pump of this invention incorporated therein;

Figure 2 is a horizontal section of thek jack along the line 2 2 in Figure 1;

Figure 3 is avertical section through the Vjack alongI the line 3-3 in Figure 2;

Figure 4 is a perspective view of the valve assembly of this invention, partially sectionalized; and

Figure 5 is acvertical section through the check valve assembly along the line. 5-5 in Figure 4.

Referringnow more particularly to the accompanying drawings in which .like numerals designate like partsthroughout the several views, the numeral I designates the base of a hydraulic jack into which is received a tubular fluid reservoir 2.V Mounted in the reservoir is a jack cylinder 3 (see Figure 2) in which a jack ram i is slidably carried.

- A pump cylinder, comprising atubular member 5,v having athread at its base, is received in a well 'I in the. jack base (see Figure `3). yA pump piston isreciprocable with the pump cylinder by means of a pump handle 9 which is fulcrumed at a pivot I!) carried by a link rod II.

Passages I2 and I3 in the pump base open to the bottom of the well, and communicate with the uid'reservoir 2 and the jack cylinder 3, respectively. These passages-are drilled into the base from one side thereof, and have their outer ends closed by plug screws I4. Removal of the plug screws gives access to tubular screen filters I5 set in the passages at the point IS where the mouths of the passages open into the bottom of the well 'I, and permits the filters to be withdrawn from the passages for cleaning.

Set into the well 'I is a unitary check valve assembly I'I. The valve cage comprises a cylindrical body or plug I'I (see Figure 4) preferably formed from bar stock and of such diameter as to be snugly received in the well, and through which a pair of ports I8 and I9 are bored parallel with the axis of the plug. Complementary but oppositely acting check valves are installed in these ports. E'ach of the ports has a counterbore 2Q, the shoulder of which 2l forms a seat for a ball valve 22, and threaded tubular spring seats 23 center compression springs 24 which yieldingly urge the balls against their seats.

The ports in the valve plug Il' are positioned to align with the ends of the passages I2 and I3 when the valve plug is set into the well. The centers of the ports are radially equi-distant from the axis of the plug, so that the plug may be inserted with either end downward. A third bore 25 extends through the plug parallel to and equidistant from the ports I8 and I9 and a pin 26, anchored in the bottom of the Well, extends into the bore 25 to locate the plug and align its ports with the passages l2 and I3.

A gasket 21 (see Figure 3) of neoprene or other suitable exible material, shaped to match an end of the plug Il', is interposed between the plug and the bottom of the well. As the tubular cylinder member 5 is threaded into the top of the well, the bottom of the cylinder member bears upon the top of the plug, pressing it down upon the gasket, which, in turn, expands horizontally against the cylindrical walls of the well to form a fluid tight seal.

Disassembly of the entire pump may thus be accomplished by unscrewing the tubular cylinder member and lifting the valve plug out of the well. By removing the plug screws which close the ends of the uid passages, the filter screens may be removed and access may be had to the entire length of the fluid passages for cleaning them.

From the foregoing description, taken in connection with the accompanying drawings, it will readily be' seen that this invention provides a reciprocating type of hydraulic pump of simplified construction, particularly suited for use with a hydraulic jack.

What I claim as my invention is:

l. In a reciprocating type hydraulic pump: a body having a bore open at one end and closed at the other, and having inlet and outlet passages opening to the bore through its closed end; a cylindrical plug, of a size to fit freely into said bore, received therein, said plug having parallel ends and having inlet and outlet ports extending axially therethrough, the spacing of said ports being such as to align with the mouths of the inlet and outlet passages in the closed end of the bore; oppositely acting check valves in said ports; means for removably securing said plug in position; and means engageable between the closed end of the' lbore and either end of the plug for properly locating the same for alignment between its ports and the mouths of the inlet and outlet passages so that said plug may be inserted with either end innermost.

2. In a reciprocating type hydraulic pump, a body having a Well and having fluid inlet and outlet passages in open communication with the bottom of the well, said passages also extending to a side wall of the body; a unitary valve assembly removably received in the bottom of said Well, said Valve assembly having intake and discharge ports extending axially therethrough and oppositely acting check valves in said ports; means for locating said valve assembly in the well with its intake and discharge ports aligned with said inlet and outlet passages; a tubular member secured to the body over the mouth of the well with a part thereof engaging the valve assembly to hold the same in place, said tubular member constituting the cylinder of the pump so that fluid is drawn through the inlet passage and the intake port to enter the cylinder and is expelled from the cylinder through the discharge port and outlet passage; filters in said inlet and outlet passages at their points of communication with the bottom of the well, said lters being removable from the passages through the ends thereof which extend to a side wall of the body; and removable means for closing the open ends of said passages.

3. As an article of manufacture, a self contained intake and discharge valve unit adapted for removable insertion into a valve chamber, comprising: a cylindrical plug having identical ends and intake and discharge passages extending axially therethrough at equi-spaced radial distances from the aXis of the plug; oppositely acting check valves in said passages; and eccentrically disposed locating means on the plug adapted to cooperate with other means in the valve chamber for properly locating the plug in the valve chamber with either end thereof innermost.

HERBERT A. THORNDIKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date '728,526 Wantz May 19, 1903 1,610,499 Dybens Dec. 14, 1926 2,049,335 Stephens July 28, 1936 

